REPORT ON MOSQUITOES. 53 



more convinced than ever that the best way to ship specimens 

 is in the water in which they are taken." 



August 14th, he writes : "It would be an interesting thing to 

 know whether the mosquito larva mouths the sand grains because 

 of the bacterial phytoglea that covers them or because of the 

 diatoms that may be attached or because it does not know any 

 more than to mull everything that comes in its way. 



"It seems to me that this question of the food of mosquito 

 larvae is very obscure. We simply know that in examining the 

 contents of their alimentary canals we find somewhat constantly, 

 certain rather gross objects. We do not know whether they 

 are the true food of the mosquito or whether they only happen 

 to be taken in by accident in the course of feeding by the insects. 



"Can the larvae live on bacteria or on any other one thing 

 alone? It seems to me this might be determined by patient 

 experimenting." 



Early in September laiwae of Ciilex syizrestris from the Passaic 

 A^alley swamps were sent in and reported upon as follows : 



"I examined the sylvestris larvae which you sent me and found 

 that their food consisted for the most part of Conferva. Below 



1 give the analysis of one larva which is typical of the lot : 



"Larva i : Synedra; Navicula; Conferva; Phacus; Pinnularia." 



Earvae of Cidex salinarius and Anopheles crucians were sent 

 in and reported upon September 14th as follows: 



"The C. nigrifuhis (salinarius) larvae arrived here from Cape 

 May in good condition, but they were destroyed by the larva of 

 some sort of a water beetle which was in the bottle and which I 

 did not notice until the following morning. The Anopheles from 

 Cape May (crucians) were examined and the principal articles 

 of food were found to be Phacus and diatoms. I give below 

 the analysis of two of them which are typical of the lot : 



"Larva i: Protococcus; Scenedesmus ; Cymbella; Navicula; 

 Pediastrum ; Cosmarium ; Phacus ; Synedra ; Cyclotella. Larva 



2 : Phacus ; Cymbella ; Cosmarium ; Scenedesmus ; Synedra ; 

 Pediastrum; Cyclotella." 



September i6th, the following report was received: 'This 

 morning I received a sample of Ciilex nigritnlus (salinarius) 

 larvae marked Matawan, September 12th. Their food is almost 

 wholly diatoms, although there was also found vegetable fiber, 

 remnants of green Algae and evidences of an infusorian of some 

 sort. I give, below, the analysis of two larvae : 



"Lai"va i: Synedra; Navicula; Pleurosigma. Larva 2: Nav- 

 icula ; Synedra ; Pleurosigma ; Difflugia ; Raphidium ; Vegetable 

 fiber." 



